title: Effects of segmental subarachnoid analgesia on arterial blood pressure, gas tensions, and pH in adult conscious cows.
abstract: Arterial blood pressure, blood gas tensions (PaCO2, PaO2), and pH (pHa) were determined in 16 adult, nonpregnant Holstein cows (620 +/- 54 kg) given subarachnoid injection of a 5% procaine hydrochloride solution at the T13-L1 intervertebral space. Analgesia, as determined by response to superficial and deep muscular pinpricks at the L1 dermatome, was delayed (onset) 7 to 15 minutes, and it lasted (duration) 28 to 83 minutes. Thoracolumbar analgesia extending between spinal cord segments T9 and L4 on 1 or both sides of the spine produced significant (P less than 0.05) increases in heart rate and decreases in respiratory rate, but otherwise had no effect (P less than 0.05) on systolic, diastolic, and mean arterial blood pressures, PaCO2, PaO2, and pHa. Similarly, no significant changes (P less than 0.05) of physiologic variables were observed in a control group of 5 cows given a subarachnoidal injection of 0.9% sodium chloride solution at 1 hour before procaine hydrochloride was injected. It was concluded that the unsedated, healthy cow tolerates segmental subarachnoid analgesia between spinal segments T9 and L4 well and that this analgesia is not adversely affected by hypoxemia, respiratory acidosis, or hypotension.
mesh_terms: D000775:Anesthesia, Spinal / Q000662:veterinary*; D000818:Animals; D001769:Blood; D001794:Blood Pressure; D002245:Carbon Dioxide / Q000097:blood*; D002417:Cattle / Q000097:blood / Q000502:physiology*; D005260:Female; D006339:Heart Rate; D006863:Hydrogen-Ion Concentration; D010100:Oxygen / Q000097:blood*; D011343:Procaine / Q000008:administration & dosage; D013346:Subarachnoid Space
chemical_list: D002245:Carbon Dioxide; D011343:Procaine; D010100:Oxygen